Archive for the ‘JSON’ Tag

In a recent project I was facing the problem that a JSON interface had to be added to an already existing XML interface. The XML was rendered using JSPs. That’s fine and I didn’t want to change that. I also didn’t want to duplicate the JSPs by writing additional JSPs that generate JSON. The easiest solution that came into my mind was to add a simple servlet filter that converts the generated XML to JSON on the fly when JSON format is requested.

In our web application the desired format (XML or JSON) was added as a request parameter to the HTTP request). All the servlet filter has to do is to check this parameter to decide whether the XML should be converted to JSON.

In order to compile and use the code you also need the following libraries:

The JsonResponseWrapper does the XML to JSON conversion. Please note that this implementation buffers the complete XML in memory. This approach is not appropriate for very large XML, but it was working very well for our application:

The code was pretty straight forward to write. But maybe it is still helpful for someone who has a similar problem. It can be optimized to use a streaming approach versus the in memory buffering of the XML. But that wasn’t needed for my purposes, so I leave this up to you. ;-)